PS1Digital Update: New FPGA, Reclocking Features

On April 1st 2020, Dan “citrus3000psi” Kunz tweeted some updates on the PS1Digital (nee, PS1HDMI) project. The PS1Digital, like the DCDigital, is a hardware modification that adds HDMI ports to compatible consoles by tapping in to the digital video and audio signals on their respective motherboards. While high-quality analog video signals can look excellent on modern displays when paired with scalers like the OSSC/RetroTink/Framemeister, mods like these have added features, higher quality, and less latency thanks to the purely digital nature of their signal path. Although a release date still has not been set, Dan has referred to the PS1Digital as “…getting really close [to completion],”.

Some interesting points from the Twitter thread:

Like the DCDigital before it, the PS1Digital will also have WiFi functionality. The DCDigital currently only uses this chip to download firmware updates directly from the DCDigital project, but the PS1Digital will expand upon that functionality by doubling as a wireless Serial I/O Port. Considering that the PS1Digital replaces the PSX’s Serial I/O Port with an HDMI connector, this is a relief for users that enjoyed the Link Cable multiplayer features in some games. As an added bonus, the WiFi chip in the PS1Digital has been upgraded from the one in the DCDigital, providing a faster and more stable signal.

The FPGA in the PS1Digital has been upgraded from a MAX10 to a Cyclone10. The takeaway here is that the Cyclone10 operates at a lower temperature and provides more resources to the PS1Digital’s dev team, which could lead to an expanded feature set—advanced deinterlacing for 480i games and improved scaling algorithms, for example.

The PS1Digital has mod-chip functionality built in, which is based off the open source PSNee project. This functionality circumvents the PSX’s copy protection (all consoles) and region coding (NTSC-U and PAL consoles only), allowing you to access the PSX’s worldwide library. The PS1Digital can also generate its own clock signal, which has the affect of letting your PSX switch between 50Hz and 60Hz output depending on the software you’re running. To reiterate though, NTSC-J (aka, Japanese) PSX consoles have added region checks that the PS1Digital won’t be able to circumvent, so those consoles are only able to run NTSC-J games for now.

Dan confirmed that only SCPH-55XX and 70XX series consoles are currently supported, and may be the only consoles ever supported by PS1Digital. The PSX hardware platform has a staggering number of revisions and some of them simply don’t expose the digital signals that the PS1Digital needs to generate its HDMI output. The current mod requires four flex cables to function, so any accommodations for other console revisions would likely require a massive redesign. If the PS1Digital is a mod you’re interested in, it’d be a good idea to find a compatible PSX instead of waiting for the possibility that support would expand.

Lastly, the PS1Digital’s installation and operation shouldn’t conflict with the modifications required for the PSIO. For those unaware, the PSIO is a Playstation optical drive emulator developed by Cybdyn system that uses a mod chip and external hardware to run PSX games from an SD card.

Again, while no release date has been set it would appear that the PS1Digital’s release isn’t too far off. It will be fascinating to see it in the wild, especially considering that the PS1Digital is purportedly a proving ground for features that will eventually make their way in to a PS2Digital mod…